/5 wirering harness

[schrader7032]

Bill -

Are you dropping in a brand new harness or doing all the rewire yourself using the diagram? From what I've heard people say, it will be a nightmare to make up your own harness. Getting the correct colors for the wires is next to impossible...if you're the only one to own this bike in the future, maybe no big deal. But the next owner will curse loudly when they try and troubleshoot the bike. Wire sizing may also be an issue. Most suggest dropping in a new BMW harness as the best way to go.

Whatever you do, take lots of notes and/or pictures as you take things apart. This will greatly assist in the reassembly. From individual connections to wire routing...this will all be critical when going back together.

I take it you still have the nail for a key in the bucket, with the circuit board on the inside? I understand that you need to be careful in removing the circuit board...it's held in with four small metal tabs. Only move the tabs enough to get the board to clear. Any excess movement will lead to breakage and there's no real way to repair that except probably to buy a new bucket.

Does your bike have any fuses in it? I'm thinking it doesn't...it would be a good idea to add a fuse to the main power line. You should also make this mod to the starter relay:

http://bmwmotorcycletech.info/slash5cricket.htm

Will you be retaining the old charging system? I think you have the 180 watt system? With some other changes, you could upgrade to the 280 watt alternator for a little room in the power category. I think there's been some recent discussion on this forum about doing that.

Here's another electrical mod that might be a good idea:

http://bmwmotorcycletech.info/genlampresistor.htm

If the lamp for the generator burns out, you won't be charging the battery. This modification ensures that you will still get good charging in that situation. It's a backup to the light. The light's still important, but this prevents you from being stranded if the light goes out.

Document a lot...and then document so more...I guess that's what I would suggest.

Kurt in S.A.

[mearns4389]

Thank you Kurt - I bought a new frame harness and engine harness. I don't know if I needed the engine harness but it was not that expensive, so what the heck. The bike does have fuses in the head light. I will read the 'gen lamp' and 'starter relay' articles you sugested. I still have the 'nail'. If I have to drop the circut board I suspect I will be pulling the speedo out also. One of the bulb holders is cracked and the head light block wire holders (push/springs) wants to fall apart - holders wants to come out of block. Maybe I should think about a new one of these (used?) I might just buy or borrow a digital camera to take lots of pistures - great idea. I know some one with a stock /5 and will take some shots of the inside of his bucket. I still have a few months to think about this and gather things and thoughts. Thanks again for such a timely response. -Bill

[VBMWMO]

When the weather starts to warm I will be in my garage starting a new project. This past summer I bought a 72 R75/5. Most of the bike is in beautiful condition - but - a mouse or 2 had made a home in the head light bucket. I think the wirering had also been messed with before this. I want to install a whole new wirering harness. I purchased a beautiful laminated wirering diagram from "somebodys garage". I understand the basics(I hope), but am looking for any pearls. Are there any "make sure you don't ......." or "be sure to ..... before you ..... and never .....". I understand that working in the /5 bucket is tedious. Oh well, this is what we do for fun - I think? Thanks for any thoughts. -Bill